混燃的稻壳飞灰特性的试验研究

Experimental Study of the Flying Ash Characteristics of Mixed Burned Rice Husks

在某300MW机组煤粉锅炉上进行稻壳掺烧试验,对掺烧的稻壳灰的微观形貌、化学性质和孔隙结构等性质进行了试验分析。主要结论为:稻壳灰的物相以石英、鳞石英和方石英晶形为主,存在少量莫来石晶体。稻壳灰形状呈现大粒径的不规则片状灰粒,稻壳灰的凸面形成波状的熔融的状态伴有少量泡状孔隙,稻壳灰的凹面有丰富的孔隙结构。在常量元素分析结果中,稻壳灰中SiO2的含量高达97.42%,稻壳灰中的Al2O3、K2O、CaO含量低。稻壳灰的孔隙的平均孔径为9.704nm,注汞体积为0.1811cm3/g,样品的比表面积为74.6332m2/g,从共燃飞灰中分离出的稻壳灰可以作为多孔材料使用。

On a 300 MW pulverized coal-fired boiler in a power plant, a mixed burning test was conducted of rice husks. The microscopic-morphological appearance, chemical properties and pore structure etc. of the ash produced by the rice husks in the mixed burning were tested and analyzed. The authors have mainly concluded that quartz, scale quartz and cristobalite in the crystal form predominate in the rice husk-produced ash physical phase and there exists a small amount of mullite crystal. The rice husk-formed ash appears in the form of irregular slice-shaped ash particles with large diameters. The convex surface of the husk-formed ash is of a wave shape in a melt state accompanied by a small number of bubble pores. The concave surface of the husk ash is abundant in pore structures. In the analytic results of constant elements, the content of SiO2 in the husk-formed ash can be as high as 97.42%. However, the content of Al2O3, K2O and CaO in the ash is low. The average diameter of the pores in the husk-formed ash is 9.704 nm, mercury filled volume amounts to 0.181 1 cm3/g and the specific surface area of the sample totals 74.633 2 m2/g.The husk-formed ash segregated from the fly ash after a co-firing can be used as porous materials.